Self-stabilizing skateboard

ABSTRACT

A self-propelled, one-wheeled vehicle may include a board having two deck portions each having a concave front footpad configured to receive a foot of a rider, and a wheel assembly disposed between the deck portions. The concave front footpad has a rider detection sensor in the form of a membrane switch conforming to the shape of the footpad (e.g., facilitated by one or more slots formed in the membrane switch). A motor assembly drives the vehicle in response to board orientation and rider detection information.

CROSS-REFERENCES

The following applications and materials are incorporated herein, intheir entireties, for all purposes: U.S. Provisional Patent ApplicationSer. No. 63/217,162, filed Jun. 30, 2021; U.S. patent application Ser.No. 17/506,551, now U.S. Pat. No. 11,273,364; U.S. patent applicationSer. No. 17/695,586, filed Mar. 15, 2022.

FIELD

This disclosure relates to self-stabilizing electric vehicles. Morespecifically, the disclosed embodiments relate to self-stabilizingtiltable skateboards having improved mechanical and electronic controlsystems.

SUMMARY

The present disclosure provides systems, apparatuses, and methodsrelating to self-stabilizing skateboards. In some examples,

In some examples, a self-balancing electric vehicle includes: a wheelassembly including a wheel having an axis of rotation; a board includinga central opening to accommodate the wheel, such that the board istiltable about the wheel, first and second deck portions of the boardeach configured to receive a left or right foot of a rider orientedgenerally parallel to the axis of rotation of the wheel; a riderdetection sensor comprising a membrane switch having one or morepressure transducers, wherein the membrane switch is disposed on a firstfootpad of the first deck portion; an electric hub motor configured todrive the wheel; and a controller configured to receive orientationinformation indicating an orientation of the board and to cause the hubmotor to propel the board based on the orientation information and onrider detection information from the rider detection sensor; wherein thefirst footpad has a concave-up profile in a direction parallel to theaxis of rotation of the wheel, and the membrane switch conforms to theconcave-up profile of the first footpad.

In some examples, a self-balancing electric vehicle includes: a boardincluding a frame, a first deck portion disposed at a first end portionof the frame, and a second deck portion disposed at a second end portionof the frame, the first and second deck portions each configured toreceive a left or right foot of a rider oriented generally perpendicularto a direction of travel of the board; a wheel assembly including awheel rotatable about an axle, wherein the wheel is disposed between andextends above and below the first and second deck portions; a riderdetection sensor comprising a membrane switch, wherein the membraneswitch is disposed on a first footpad of the first deck portion; a motorassembly configured to rotate the wheel about the axle to propel thevehicle; and an electronic controller configured to receive orientationinformation indicating an orientation of the board and to cause themotor assembly to propel the vehicle based on the orientationinformation and on rider detection information from the rider detectionsensor; wherein the first footpad has a concave-up profile in a heel-toedirection, and the membrane switch conforms to the concave-up profile ofthe first footpad.

In some examples, a self-balancing electric vehicle includes: a wheelassembly including a wheel driven by a hub motor about an axle; a boardincluding an aperture to accommodate the wheel, such that the board istiltable about the wheel, first and second deck portions of the boardeach configured to receive a left or right foot of a rider orientedgenerally parallel to the axle; a rider detection sensor comprising amembrane switch, wherein the membrane switch is disposed on a firstfootpad of the first deck portion; and a controller configured to causethe hub motor to propel the board based on board orientation informationand on rider detection information from the rider detection sensor;wherein the first footpad has a concave-up profile in a directionparallel to the axle, and the membrane switch conforms to the concave-upprofile of the first footpad.

Features, functions, and advantages may be achieved independently invarious embodiments of the present disclosure, or may be combined in yetother embodiments, further details of which can be seen with referenceto the following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of an illustrative one-wheeled skateboard inaccordance with aspects of the present disclosure.

FIG. 2 is another isometric view of the skateboard of FIG. 1 , takenfrom a different vantage point.

FIG. 3 is a first end elevation view of the skateboard of FIG. 1 .

FIG. 4 is a second end elevation view of the skateboard of FIG. 1 .

FIG. 5 is a first side elevation view of the skateboard of FIG. 1 .

FIG. 6 is a second side elevation view of the skateboard of FIG. 1 .

FIG. 7 is a top plan view of the skateboard of FIG. 1 .

FIG. 8 is a bottom plan view of the skateboard of FIG. 1 .

FIG. 9 is a partially exploded, isometric view of a first deck portionof the skateboard of FIG. 1 .

FIG. 10 is an exploded view of a footpad of the first deck portion ofFIG. 9 .

FIG. 11 is an isometric sectional view of the first deck portion of FIG.9 .

FIG. 12 is another isometric sectional view of the first deck portion ofFIG. 9 .

FIG. 13 is a top plan view of a rider detection system in accordancewith aspects of the present disclosure.

FIG. 14 is a partially exploded, isometric view depicting a bumper foruse with the first deck portion of FIG. 9 .

FIG. 15 is another partially exploded, isometric view depicting thebumper of FIG. 14 .

FIG. 16 is an elevated view of the first deck portion of the first deckportion of FIG. 9 , without the bumper of FIG. 14 .

FIG. 17 is a partially exploded, bottom plan view depicting the bumperof FIG. 14 .

FIG. 18 is a bottom plan view of the first deck portion of FIG. 9 .

FIG. 19 is a partially exploded, isometric view depicting a bumper foruse with a second deck portion of the skateboard of FIG. 1 .

FIG. 20 is a partially exploded, isometric view depicting another bumperfor use with the first or second deck portion of the skateboard of FIG.1 .

FIG. 21 is a side elevation view of a charging port of the skateboard ofFIG. 1 .

FIG. 22 is a schematic block diagram of a control system suitable foruse with the skateboard of FIG. 1 .

DETAILED DESCRIPTION

Various aspects and examples of a self-stabilizing skateboard, as wellas related methods, are described below and illustrated in theassociated drawings. Unless otherwise specified, a self-stabilizingskateboard in accordance with the present teachings, and/or its variouscomponents, may contain at least one of the structures, components,functionalities, and/or variations described, illustrated, and/orincorporated herein. Furthermore, unless specifically excluded, theprocess steps, structures, components, functionalities, and/orvariations described, illustrated, and/or incorporated herein inconnection with the present teachings may be included in other similardevices and methods, including being interchangeable between disclosedembodiments. The following description of various examples is merelyillustrative in nature and is in no way intended to limit thedisclosure, its application, or uses. Additionally, the advantagesprovided by the examples and embodiments described below areillustrative in nature and not all examples and embodiments provide thesame advantages or the same degree of advantages.

This Detailed Description includes the following sections, which followimmediately below: (1) Definitions; (2) Overview; (3) Examples,Components, and Alternatives; (4) Advantages, Features, and Benefits;and (5) Conclusion. The Examples, Components, and Alternatives sectionis further divided into subsections, each of which is labeledaccordingly.

Definitions

The following definitions apply herein, unless otherwise indicated.

“Comprising,” “including,” and “having” (and conjugations thereof) areused interchangeably to mean including but not necessarily limited to,and are open-ended terms not intended to exclude additional, unrecitedelements or method steps.

Terms such as “first”, “second”, and “third” are used to distinguish oridentify various members of a group, or the like, and are not intendedto show serial or numerical limitation.

“AKA” means “also known as,” and may be used to indicate an alternativeor corresponding term for a given element or elements.

The terms “inboard,” “outboard,” “forward,” “rearward,” and the like areintended to be understood in the context of a host vehicle on whichsystems described herein may be mounted or otherwise attached. Forexample, “outboard” may indicate a relative position that is laterallyfarther from the centerline of the vehicle, or a direction that is awayfrom the vehicle centerline. Conversely, “inboard” may indicate adirection toward the centerline, or a relative position that is closerto the centerline. Similarly, “forward” means toward the front portionof the vehicle, and “rearward” means toward the rear of the vehicle. Inthe absence of a host vehicle, the same directional terms may be used asif the vehicle were present. For example, even when viewed in isolation,a device may have a “forward” edge, based on the fact that the devicewould be installed with the edge in question facing in the direction ofthe front portion of the host vehicle.

“Coupled” means connected, either permanently or releasably, whetherdirectly or indirectly through intervening components.

“Resilient” describes a material or structure configured to respond tonormal operating loads (e.g., when compressed) by deforming elasticallyand returning to an original shape or position when unloaded.

“Rigid” describes a material or structure configured to be stiff,non-deformable, or substantially lacking in flexibility under normaloperating conditions.

“Elastic” describes a material or structure configured to spontaneouslyresume its former shape after being stretched or expanded.

“Processing logic” describes any suitable device(s) or hardwareconfigured to process data by performing one or more logical and/orarithmetic operations (e.g., executing coded instructions). For example,processing logic may include one or more processors (e.g., centralprocessing units (CPUs) and/or graphics processing units (GPUs)),microprocessors, clusters of processing cores, FPGAs (field-programmablegate arrays), artificial intelligence (AI) accelerators, digital signalprocessors (DSPs), and/or any other suitable combination of logichardware.

A “controller” or “electronic controller” includes processing logicprogrammed with instructions to carry out a controlling function withrespect to a control element. For example, an electronic controller maybe configured to receive an input signal, compare the input signal to aselected control value or setpoint value, and determine an output signalto a control element (e.g., a motor or actuator) to provide correctiveaction based on the comparison. In another example, an electroniccontroller may be configured to interface between a host device (e.g., adesktop computer, a mainframe, etc.) and a peripheral device (e.g., amemory device, an input/output device, etc.) to control and/or monitorinput and output signals to and from the peripheral device.

“Providing,” in the context of a method, may include receiving,obtaining, purchasing, manufacturing, generating, processing,preprocessing, and/or the like, such that the object or materialprovided is in a state and configuration for other steps to be carriedout.

In this disclosure, one or more publications, patents, and/or patentapplications may be incorporated by reference. However, such material isonly incorporated to the extent that no conflict exists between theincorporated material and the statements and drawings set forth herein.In the event of any such conflict, including any conflict interminology, the present disclosure is controlling.

Overview

In general, a self-balancing skateboard in accordance with the presentteachings may include a board having a two deck portions on either sideof a central opening. In examples described below, each deck portion isconfigured to support a respective foot of a user oriented as on astandard skateboard, such that the vehicle is ridden with the userfacing approximately ninety degrees to the direction of travel. A singlewheel (or side-by-side wheels) is supported in the central opening on anaxle and driven by a motor (e.g., a hub motor). The board is thereforetiltable about the axis of the wheel (i.e., about an axis of rotationdefined by the axle). An onboard electronic controller is configured toreceive orientation information indicating an orientation of the board.In response to this orientation information, the controller causes thehub motor to propel the board, and provides a self-stabilizing feature.

In some examples, the skateboard includes a handle pivotably coupled toa portion of the board, such as to an axle mounting block of the board.The handle can be pivoted between a stowed configuration and a deployedconfiguration. In the stowed configuration, the handle is flipped up (orin some examples down) adjacent the hub motor. In the deployedconfiguration, the handle is pivoted down (or up) to extend away fromthe hub motor and provide a graspable carrying handle for the user.

In some examples, the vehicle has a fender, which is interchangeablewith a substitute “fender delete,” which covers the connection points ofthe fender to the vehicle but does not extend to cover the vehiclewheel. The fender is removably coupled to a frame of the board and spansthe opening between the deck portions. The fender has an arched portioncovering an upper surface of the tire and a peripheral flange extendingaround the opening. The fender delete has a similar appearance, withoutthe arched portion. In other words, it surrounds the periphery of theopening but does not overarch the tire or wheel.

In some examples, the vehicle includes a status indicator (e.g., abattery charge indicator) including a plurality of illuminators viewablethrough a slot formed in an upper surface of the board. This enableseasy viewing for the rider.

The vehicle includes footpads having concave upper surfaces configuredto reduce foot fatigue and improve user control. One or more sensorsembedded within the concave footpads have a three-dimensional shape toconform to the footpad concavity, and are configured to provide riderdetection functionality.

In some examples, the footpad sensors comprise a plastic laminate whichcan bend or curve in one direction but cannot easily bend in a compoundcurvature, e.g., without damaging internal circuitry. To accommodate thecompound curvature of the concave footpad surface, slots (AKA “cuts,”“slits,” “isolines,” or “channels”) are provided along specific lines(e.g., diagonal from the outer corners). The slots facilitate conformingto the compound curvature of the footpad while relieving stress on themembrane.

In some examples, the footpad surface provides a concave surface bycreating multiple regions, wherein each region has substantial curvatureonly in a single direction. In some examples, sensor traces of themembrane switch are aligned with the direction of curvature to preventbuckling. In some examples, ribs or ridges protrude from the footpadsurface to fill in or retain the sensor slots. In some examples,computational flattening is utilized to convert the desired curvedsurface of the membrane into a flat pattern for manufacturing.

In some examples, the concave footpads include at least two portions: arigid substrate (e.g., plastic) and a resilient layer (e.g., rubber orfoam) disposed thereon. The rigid substrate may comprise a thermoplasticpolymer, e.g., acrylonitrile butadiene styrene (ABS), polyethylene (PE),polyvinyl chloride (PVC), and/or another suitable material. Theresilient layer may comprise an elastomer, e.g., a synthetic and/ornatural rubber or another suitably resilient material, e.g., a highdensity foam. In some examples, the resilient layer may include aplurality of downward-facing protrusions configured to be received incorresponding apertures in the rigid substrate to provide additionalmechanical stability. In some examples, these protrusions are formedduring an overmolding or injection molding process. In some examples,the injection molding process results in portions of the resilient layerpassing through and around apertures and features of the underlyingrigid substrate, such that the resilient layer and the rigid substratecannot be separated mechanically in a nondestructive manner.

Aspects of the control systems described herein (e.g., electroniccontrollers, motor controllers, etc.) may be embodied as a computermethod, computer system, or computer program product. Accordingly,aspects of the present control systems may include processing logic andmay take the form of an entirely hardware embodiment, an entirelysoftware embodiment (including firmware, resident software, micro-code,and the like), or an embodiment combining software and hardware aspects,all of which may generally be referred to herein as a “circuit,”“module,” or “system.” Furthermore, aspects of the present controlsystems may take the form of a computer program product embodied in acomputer-readable medium (or media) having computer-readable programcode/instructions embodied thereon.

Any combination of computer-readable media may be utilized.Computer-readable media can be a computer-readable signal medium and/ora computer-readable storage medium. A computer-readable storage mediummay include an electronic, magnetic, optical, electromagnetic, infrared,and/or semiconductor system, apparatus, or device, or any suitablecombination of these. More specific examples of a computer-readablestorage medium may include the following: an electrical connectionhaving one or more wires, a portable computer diskette, a hard disk, arandom access memory (RAM), a read-only memory (ROM), an erasableprogrammable read-only memory (EPROM or Flash memory), an optical fiber,a portable compact disc read-only memory (CD-ROM), an optical storagedevice, a magnetic storage device, and/or any suitable combination ofthese and/or the like. In the context of this disclosure, acomputer-readable storage medium may include any suitablenon-transitory, tangible medium that can contain or store a program foruse by or in connection with an instruction execution system, apparatus,or device.

A computer-readable signal medium may include a propagated data signalwith computer-readable program code embodied therein, for example, inbaseband or as part of a carrier wave. Such a propagated signal may takeany of a variety of forms, including, but not limited to,electro-magnetic, optical, and/or any suitable combination thereof. Acomputer-readable signal medium may include any computer-readable mediumthat is not a computer-readable storage medium and that is capable ofcommunicating, propagating, or transporting a program for use by or inconnection with an instruction execution system, apparatus, or device.

Program code embodied on a computer-readable medium may be transmittedusing any appropriate medium, including but not limited to wireless,wireline, optical fiber cable, RF, and/or the like, and/or any suitablecombination of these.

Computer program code for carrying out operations for aspects of thepresent control systems may be written in one or any combination ofprogramming languages, including an object-oriented programming languagesuch as Java, C++, and/or the like, and conventional proceduralprogramming languages, such as C. Mobile apps may be developed using anysuitable language, including those previously mentioned, as well asObjective-C, Swift, C #, HTML5, and the like. The program code mayexecute entirely on a user's computer, partly on the user's computer, asa stand-alone software package, partly on the user's computer and partlyon a remote computer, or entirely on the remote computer or server. Inthe latter scenario, the remote computer may be connected to the user'scomputer through any type of network, including a local area network(LAN) or a wide area network (WAN), and/or the connection may be made toan external computer (for example, through the Internet using anInternet Service Provider).

Aspects of the present control systems are described below withreference to flowchart illustrations and/or block diagrams of methods,apparatuses, systems, and/or computer program products. Each blockand/or combination of blocks in a flowchart and/or block diagram may beimplemented by computer program instructions. The computer programinstructions may be provided to a processor of a general purposecomputer, special purpose computer, or other programmable dataprocessing apparatus to produce a machine, such that the instructions,which execute via the processor of the computer or other programmabledata processing apparatus, create means for implementing thefunctions/acts specified in the flowchart and/or block diagram block(s).In some examples, machine-readable instructions may be programmed onto aprogrammable logic device, such as a field programmable gate array(FPGA).

These computer program instructions can also be stored in acomputer-readable medium that can direct a computer, other programmabledata processing apparatus, and/or other device to function in aparticular manner, such that the instructions stored in thecomputer-readable medium produce an article of manufacture includinginstructions which implement the function/act specified in the flowchartand/or block diagram block(s).

The computer program instructions can also be loaded onto a computer,other programmable data processing apparatus, and/or other device tocause a series of operational steps to be performed on the device toproduce a computer-implemented process such that the instructions whichexecute on the computer or other programmable apparatus provideprocesses for implementing the functions/acts specified in the flowchartand/or block diagram block(s).

Any flowchart and/or block diagram in the drawings is intended toillustrate the architecture, functionality, and/or operation of possibleimplementations of systems, methods, and computer program productsaccording to aspects of the present control systems. In this regard,each block may represent a module, segment, or portion of code, whichcomprises one or more executable instructions for implementing thespecified logical function(s). In some implementations, the functionsnoted in the block may occur out of the order noted in the drawings. Forexample, two blocks shown in succession may, in fact, be executedsubstantially concurrently, or the blocks may sometimes be executed inthe reverse order, depending upon the functionality involved. Each blockand/or combination of blocks may be implemented by special purposehardware-based systems (or combinations of special purpose hardware andcomputer instructions) that perform the specified functions or acts.

Examples, Components, and Alternatives

The following sections describe selected aspects of illustrativeself-stabilizing skateboards, as well as related systems and/or methods.The examples in these sections are intended for illustration and shouldnot be interpreted as limiting the scope of the present disclosure. Eachsection may include one or more distinct embodiments or examples, and/orcontextual or related information, function, and/or structure.

A. Illustrative Electric Vehicle

As shown in FIGS. 1-22 , this section describes an illustrative electricvehicle 100. Vehicle 100 is an example of the electric vehiclesdescribed in the Overview. FIGS. 1-8 show vehicle 100 from variousviewpoints. FIGS. 9-22 are various sectional views, exploded views, andother views showing arrangements of components of the vehicle.

Vehicle 100 is a single-wheeled, self-stabilizing skateboard including aboard 102 (AKA a tiltable portion of the vehicle, a platform, and/or afoot deck) having a frame 104 supporting a first deck portion 106 and asecond deck portion 108 defining an opening 110 therebetween. Board 102may generally define a plane. Each deck portion 106, 108 (or foot padportion thereof) is configured to receive and support a left or rightfoot of a rider oriented generally perpendicular to a direction oftravel of the board (see FIGS. 1 and 2 ), the direction of travelgenerally indicated at D. First and second deck portions 106, 108 may beformed of a same physical piece, may be unitary with the frame, or maybe separate pieces. First and second deck portions 106, 108 may beincluded in the definition of board 102.

Vehicle 100 includes a wheel assembly 112 having a rotatableground-contacting element 114 (e.g., a tire, wheel, or continuous track)disposed between and extending above first and second deck portions 106,108, and a motor assembly 116 configured to rotate ground-contactingelement 114 to propel the vehicle. As shown in FIG. 1 and elsewhere,vehicle 100 may include exactly one ground-contacting element, disposedbetween the first and second deck portions. In some examples, vehicle100 may include a plurality of ground-contacting elements (e.g., coaxialwheels).

Wheel assembly 112 is disposed between first and second deck portions106, 108, and ground-contacting element 114 is coupled to motor assembly116. Motor assembly 116 includes an axle 126 (AKA a shaft), whichcouples motor assembly 116 to board 102, e.g., by one or more axlemounts and one or more fasteners, such as a plurality of bolts. In someexamples, axle 126 is coupled to board 102 by way of a suspensionsystem. In some examples, motor assembly 116 is configured to rotateground-contacting element 114 around (or about) axle 126 to propelvehicle 100. For example, motor assembly 116 may include an electricmotor, such as an electric hub motor, configured to rotateground-contacting element 114 about axle 126 to propel vehicle 100 alongthe ground. For convenience, ground-contacting element 114 ishereinafter referred to as a tire or wheel, although other suitableembodiments may be provided.

First and second deck portions 106, 108 are located on opposite sides ofwheel assembly 112, with elongate board 102 being dimensioned toapproximate a skateboard. In some embodiments, the board approximates alongboard skateboard, snowboard, surfboard, or may be otherwisedesirably dimensioned. In some examples, deck portions 106, 108 of board102 are at least partially covered with non-slip material portions 128,130 (e.g., grip tape or other textured material) to aid in rider controland protect underlying components.

Frame 104 may include any suitable structure configured to rigidlysupport the deck portions and to be coupled (directly or indirectly) tothe axle of the wheel assembly, such that the weight of a rider issupported on tiltable board 102, and the board has a fulcrum at theaxle. Frame 104 may include one or more frame members 118, on which deckportions 106 and 108 may be mounted, and which may further supportadditional elements and features of the vehicle, such as a charging port172, a switch 170, and end bumpers 122, 124, as well as lightingassemblies, battery and electrical systems, electronics, controllers,and the like (see, e.g., FIG. 22 and corresponding description below).

Deck portions 106 and 108 may include any suitable structures configuredto support the feet of a rider, such as non-skid surfaces 128, 130, aswell as vehicle-control features, such as various sensors and a riderdetection system 168. In some examples, the rider detection systemincludes a rider detection sensor in the form of a pressure switch or astrain gauge in communication with a controller of the vehicle. Therider detection sensor may include a plurality of pressure switcheshoused in a waterproof casing to form a membrane switch. Deck portions106 and 108, as well as related features, are described in furtherdetail below.

Shaft or axle 126 of motor assembly 116 is coupled to frame 104, asshown in FIG. 1 . For example, the axle may be directly attached toframe 104, or may be coupled to the frame at each end through arespective connection or axle mounting block 132, 134 (also referred toas an axle mount or a simply a mounting block). Axle 126 may be boltedor otherwise affixed to mounting blocks 132, 134, e.g., at either end,which in turn may be bolted or affixed to frame 104 using suitablefasteners (e.g., by bolts 136, 138). Through-holes 140, 142 may beprovided in frame 104 for receiving fasteners of the axle and mountingblocks, thereby securing the components together. In some examples, asmentioned above, axle 126 is coupled to frame 104 by a suspension system(not shown).

Vehicle 100 has a pitch axis A1, a roll axis A2, and a yaw axis A3 (seeFIG. 1 ). Pitch axis A1 is the axis about which tire 114 is rotated bymotor assembly 116. For example, pitch axis A1 may pass through axle 126(e.g., pitch axis A1 may be parallel to and aligned with an elongatedirection of axle 126). Roll axis A2 is perpendicular to pitch axis A1,and extends in direction D (i.e., the direction in which vehicle 100 ispropelled by the motor assembly). For example, roll axis A2 maycorrespond to a long axis of board 102. Yaw axis A3 is perpendicularboth to pitch axis A1 and to roll axis A2. Yaw axis A3 is normal to aplane defined by deck portions 106, 108, as shown in FIG. 1 . Axes A1and A2 are analogous to the Y and X axes (e.g., corresponding tohorizontal), while axis A3 is analogous to the Z axis (e.g.,corresponding to vertical). Pitch axis A1 and roll axis A2 may lie in aplane of the board. In some embodiments, the pitch and roll axes maydefine this plane.

Tire 114 may be wide enough in a heel-toe direction (e.g., in adirection parallel to pitch axis A1) that the rider can balance in theheel-toe direction manually, i.e., by shifting his or her own weight,without automated assistance from the vehicle. Tire 114 may be tubeless,or may be used with an inner tube. In some examples, tire 114 may be anon-pneumatic tire. For example, tire 114 may be “airless,” solid,and/or may comprise a foam. Tire 114 may have a profile such that therider can lean vehicle 100 over an edge of the tire (and/or pivot theboard about roll axis A2 and/or yaw axis A3) through heel and/or toepressure to facilitate cornering of vehicle 100.

Motor assembly 116 may include any suitable driver of tire/wheel 114,such as an electric hub motor 144 mounted within wheel 114. The hubmotor may be internally geared or may be direct-drive. The use of a hubmotor facilitates the elimination of chains and belts, and enables aform factor that considerably improves maneuverability, weightdistribution, and aesthetics. Mounting tire 114 onto hub motor 144 maybe accomplished by either a split-rim design that may use hub adapters,which may be bolted on to hub motor 144, or by casting a housing of thehub motor such that it provides mounting flanges for a tire beaddirectly on the housing of the hub motor.

With continuing reference to FIGS. 1-8 and FIGS. 14-19 , first bumper122 (AKA the front bumper) is integrated into (or removably coupled to)a first end 146 of board 102 proximate first deck portion 106, andsecond bumper 124 (AKA the rear bumper) is integrated into (or removablycoupled to) a second end 148 of board 102 proximal second deck portion108. Bumpers 122, 124 may be referred to as skid pads, and may bereplaceable and/or selectively removable. For example, the bumpers mayinclude replaceable polymer parts or components, and/or may each beentirely replaceable as a single (e.g., monolithic) piece. In someexamples, bumpers 122, 124 each comprise a thermoplastic polymer, suchas acrylonitrile butadiene styrene (ABS). In some embodiments, thebumpers are configured to allow the rider to bring vehicle 100 to a stopin an angled orientation (e.g., by setting one end of the board againstthe ground after the rider removes their foot from a rider detectiondevice or switch, which is described below in further detail). In thiscontext, the bumpers may be configured to be abrasion-resistant and/orruggedized.

First bumper 122 and/or second bumper 124 each include a bumper body 123configured to form a distal, external end of board 102, and an expanse125 extending from body 123 to form a lower external surface of board102. In some examples, each lateral edge of expanse 125 includes alengthwise channel 127 configured to slidingly mate with a correspondinginward protrusion 129 disposed along a discrete length of each of therespective side rails of frame 104. See FIG. 16 , which is an end viewof vehicle 100 with the bumper removed. This configuration enables body123 of the bumper to be held to the frame by one or more removablefasteners at one end while the opposing end of the bumper is supportedentirely by channels 127 and protrusions 129 (i.e., without additionalfasteners).

As shown in FIGS. 17 and 18 , expanse 125 of bumper 122 includes anaperture 131 forming a carrying handle. An electronics housing (AKAenclosure) 208, described further below, disposed above expanse 125includes a corresponding recess 209 that is in registration withaperture 131 of the bumper when fully assembled, such that a user'sfingers are received by aperture 131 and recess 209 when the vehicle iscarried by this handle. Recess 209 is a blind hole (e.g., dead-ended)having dimensions corresponding to the aperture in the bumper expanse.In some examples, one or more portions of expanse 125 surroundingaperture 131 and portions of recess 209 configured to be graspedmanually by the user are coated (e.g., overmolded) with a resilientmaterial, e.g., a rubber or a soft plastic, to create a more comfortablegrip.

FIG. 19 is a partially exploded view of a rear end of vehicle 100,showing rear bumper 124 removed from the board. Bumper 124 includes bodyportion 123 and expanse 125, with a tab protruding upward from the endof the bumper to wrap around an enclosure (e.g., battery enclosure)internal to the board. Bumper 124 may be attached to board 102 usingremovable fasteners (e.g., screws or bolts) at the body end and alongthe expanse.

FIG. 20 depicts an alternative embodiment of a bumper 124′, depicted ona vehicle 100′. Bumper 124′ is generally U-shaped, having a body 133configured to form an external end of the board. A pair of legs 135, 137extend from the body to form lower longitudinal corners of the board,such that the upper surfaces of the legs of the bumper are in contactwith the bottom edges of the side rails of a frame 104′.

Each leg 135, 137 includes an inward protrusion 139 running along alength (e.g., a discrete length) of each of the legs. Protrusion 139 isconfigured to slidingly mate with a corresponding lengthwise channel 141of the vehicle, e.g., formed in a battery housing (AKA enclosure) 230′or other enclosure of the board. Body 133 of the bumper is coupled orheld to the board by one or more removable fasteners, and distal ends(ends closest to tire 114′) of legs 135, 137 are supported entirely byprotrusions 139 and channels 141 (i.e., without fasteners). Bumper 124′may be provided or utilized in examples where a battery enclosure 230′extends downward farther than adjacent side rails of the vehicle frame.In these examples, channels 141 are disposed lower than the bottom edgesof the side rails, and the enclosure extends between the two legs of thebumper to form an external surface of the board.

As shown in FIG. 1 and elsewhere, vehicle 100 further includes astowable handle 150. Handle 150 is disposed on a lateral side of wheel114, adjacent hub motor 144, and is transitionable between a firstconfiguration, in which a graspable grip portion 152 of the handle isstowed in a position proximate the hub motor, and a secondconfiguration, in which grip portion 152 is pivoted or folded into aposition extending or protruding transverse to the stowed position, suchthat the grip portion may be engaged by a hand of the user to carry ortransport the board. With the board in an operational position on asupport surface, the grip of the handle may be substantially vertical inthe first configuration (preventing breakage, interference with riding,etc.) and substantially horizontal in the second configuration. Thefirst configuration may be referred to as the “stowed” position, the“up” position, the “riding” position, the “operational” position, the“undeployed” position, and/or the “in” position. The secondconfiguration may be referred to as the “carrying” position, the “down”position, the “portable” position, the “deployed” position, and/or the“out” position.

In addition to grip portion 152, handle 150 includes a hinge 154comprising hinge knuckles 156 configured to receive a hinge pin. Handle150 may be pivotably coupled to any suitable fixed feature of thevehicle, such as the frame, fender, or axle block. In the exampledepicted in FIGS. 1-8 , handle 150 is coupled to axle mounting block 134by hinge 154, e.g., on an inboard upper side of the block. In someexamples, a magnetic tab is configured to contact and be biased toward(i.e., attracted to) mounting block 134 to retain handle 150 while inthe stowed position. In some examples, a spring-loaded hinge (e.g.,using a torsion spring) may be utilized in addition to or instead of themagnet arrangement.

Components of handle 150 may be constructed using injection-moldedplastic and/or machined or cast metal. Portions configured to be graspedmanually by the user may be overmolded using a resilient material, e.g.,a rubber or a soft plastic, to create a more comfortable grip.

Vehicle 100 may include any suitable apparatus, device, mechanism,and/or structure for preventing water, dirt, or other road debris frombeing transferred by the ground-contacting element to the rider. Forexample, vehicle 100 may include a fender (AKA a full fender) configuredto fully cover an upper periphery of tire 114. The fender is coupled toframe 104, e.g., using fasteners and/or magnetic connectors, andconfigured to prevent debris from being transferred from tire 114 to therider, such as when tire 114 is rotated about pitch axis A1.

As indicated in FIG. 22 , and depicted variously in FIGS. 2, 9, 13 , andelsewhere, the one or more electrical components of vehicle 100 mayinclude a power supply 164, a motor controller 166, a rider detectiondevice 168, a power switch 170, and a charge plug receptacle 172.Further description is provided below, with respect to FIG. 22 .

Power supply 164 may include one or more batteries (e.g., secondary orrechargeable batteries), such as one or more lithium-ion batteries thatare relatively light in weight and have a relatively high power density.In some examples, power supply 164 may include one or more lithium ironphosphate batteries, one or more lithium polymer batteries, one or morelithium cobalt batteries, one or more lithium manganese batteries, or acombination thereof. For example, power supply 164 may include sixteen(16) A123 lithium iron phosphate batteries (e.g., size 8050). Thebatteries of power supply 164 may be arranged in a 16S1P configuration,or any other suitable configuration.

Motor controller 166 will generally include suitable electronics forcontrolling the vehicle motor. For example, a microcontroller 174 and/orone or more sensors (or at least one sensor) 176 may be included in orconnected to motor controller 166 (see FIG. 22 ). At least one ofsensors 176 may be configured to measure orientation information (or anorientation) of board 102. For example, sensors 176 may be configured tosense movement of board 102 about and/or along the pitch, roll, and/oryaw axes. The motor may be configured to cause rotation of wheel 114based on the orientation of board 102. In particular, motor controller166 may be configured to receive orientation information measured by theat least one sensor of sensors 176 and to cause motor assembly 116 topropel the electric vehicle based on the orientation information. Forexample, motor controller 166 may be configured to drive hub motor 144based on received sensed movement of board 102 from sensors 176 viamicrocontroller 174 to propel and/or actively balance vehicle 100.

In general, at least a portion of the electrical components areintegrated into board 102. For example, board 102 includes a firstenvironmental enclosure that houses power supply 164, and a secondenvironmental enclosure that houses motor controller 166. Theenvironmental enclosures are configured to protect the one or moreelectrical components from being damaged, such as by water ingress.

Vehicle 100 further includes a plurality of light assemblies, such asone or more headlight and/or taillight assemblies (see, e.g., FIGS. 3and 4 ), and a battery indicator. For example, a firstheadlight/taillight assembly (or first light assembly) 180 may bedisposed on or at (and/or connected to) first end portion 146 of theboard (e.g., at a distal end portion of first deck portion 106), and asecond headlight/taillight assembly 182 may be disposed on or at (and/orconnected to) second end portion 148 of the board (e.g., at a distal endportion of second deck portion 108).

Headlight/taillight assemblies 180, 182 may be configured to reversiblylight vehicle 100. For example, assemblies 180, 182 may indicate thedirection that vehicle 100 is moving by changing color. For example, theheadlight/taillight assemblies may each include one or more high outputRGB and/or red and white LEDs (or other suitable one or moreilluminators) 184 configured to receive data from microcontroller 174(and/or a pitch sensor or sensors 176, such as a 3-axis gyro(s) 186 oraccelerometer(s) 188) and automatically change color (e.g., from red towhite, white to red, or a first color to a second color) based on thedirection of movement of vehicle 100. The first color shines in thedirection of motion and the second color shines backward (e.g., oppositethe direction of motion). For example, one or more of theheadlight/taillight assemblies (e.g., their respective illuminators) maybe coupled to microcontroller 174 via an LED driver, which may beincluded in or connected to motor controller 166.

In some embodiments, the illuminators of assemblies 180, 182 may includeRGB/RGBW LEDs. In a preferred embodiment, each LED is individuallyaddressable, such that user adjustment of lighting color is permitted.Additional functionality, such as turn signal indication/animationand/or vehicle state information (e.g., battery state, operational vs.disabled by interlock, etc.) may also be provided.

Assemblies 180, 182 and their associated illuminators may be located inand/or protected by bumpers 122, 124. For example, bumpers 122, 124 mayinclude respective apertures 200, 202, through which illuminators mayshine. Apertures 200, 202 may be dimensioned to prevent the illuminatorsfrom contacting the ground. For example, apertures 200, 202 may eachhave a depth or inset profile.

Vehicle 100 may also include a power supply status indicator,specifically a battery indicator 204 comprising one or more illuminators206 (e.g., LEDs) disposed within a housing 208 of motor controller 166.Battery indicator 204 may include any suitable illuminator(s) configuredto indicate a state of power supply 164, e.g., by way of a signalprovided to the battery indicator by the microcontroller and/or directlyor indirectly from the power supply. Battery indicator 204 is viewableby a rider, e.g., during operation of the vehicle, through an apertureor slot 210 formed in an upper side of one of the foot pads.

In this example, battery indicator 204 is an LED strip visible to therider. Seven illuminators 206 are provided, using RGB-capable LEDlights, although more or fewer may be utilized. The LED strip isprogrammable, and configured to display a battery state of charge as abar graph and/or by a color (e.g., starts green when fully charged, goesthrough yellow, to red when nearing full discharge). The LED strip mayalso flash error codes, display status of footpad zone activation (i.e.,via rider detection system 168), display alerts/alarms, blink codewarnings, and/or the like. In some examples, LED behavior may beprogrammed to disappear while riding and only fade back in when stopped(or below a threshold speed). This mode of operation prevents the riderfrom looking down while riding. One or more of the above-described modesmay be remotely selectable by a user. In some examples, the modes and,for example, a brightness adjustment, may be controllable from asoftware application running on a user's smartphone or other mobiledevice. In some examples, brightness may be based on either absolutebrightness setting, or some other variable, e.g., a time of dayadjustment (dimmer at night).

To facilitate and enhance viewing of illuminators 206 through slot 210,a portion of housing 208 includes a light pipe 212 extending fromadjacent the illuminators to (and in some examples, into) the slot.Light pipe 212 may include any suitable structure configured to transmitlight from the illuminators (e.g., mounted on a circuit board within thecontroller housing) to the slot 210. For example, light pipe 212 may bean optical fiber or a solid transparent material, and may be flexible orrigid. In this example, light pipe 212 is formed as a wide column ofsolid transparent material to cover a linear array of LED illuminatorsat a lower end and to interface with or fit into slot 210 at an upperend. In some examples, an upper portion of light pipe 212 fills slot210, thereby plugging the slot and preventing or reducing the incursionof debris and the like. Light pipe 212 may be formed as a single piecewith a lid 214 of housing 208, which is coupled to the base of thehousing. Some or all of housing 208 may comprise a transparent material(e.g., clear polycarbonate), which may include optical windows for theheadlights and battery indicator LEDs. Areas of the housing that are notused as optical windows may be aggressively textured (e.g., on both theinside and outside surfaces) to prevent visibility into the controllerhousing. Using a clear material with etching or texturing, rather thanassembling clear windows into an opaque controller housing, helps tosimplify construction and prevent potential seal failure points.

Turning to FIG. 9 , an illustrative arrangement of components within thefront deck portion will now be described. FIG. 9 is a partially explodedview of front deck portion 106. As depicted, deck portion 106, in thisexample, includes nonskid sheet 128, which is layered on a membraneswitch 220 (see FIG. 13 ) of rider detection system 168, which in turnis disposed on a first footpad 222 (AKA the front footpad). Footpad 222may include any suitable rigid, generally planar structure configured tosupport the rider on board 102. In this example, footpad 222 is thickeron one end, such that an upper surface of footpad 222 is ramped orcurved upward slightly toward end 146 of the board. Footpad 222 iscoupled directly to frame 104, and supported thereon. One or moreapertures 224 are provided in footpad 222 for receiving conductors(e.g., wires) to connect membrane switch 220 with motor controller 166.Motor controller 166 is housed (at least partially) in housing 208,which is disposed under footpad 222 within the board. An undercarriageis provided by an extension of front bumper 122 (e.g., the expanse ofthe bumper), or in some examples by a separate housing or expanse ofrigid material.

Deck portion 108, similarly includes nonskid sheet 130, which isdisposed on a second footpad 226 (AKA the rear footpad). Footpad 226 mayinclude any suitable rigid, generally planar structure configured tosupport the rider on board 102. In this example, footpad 226 is thickeron one end, such that an upper surface of footpad 226 is curved upwardslightly toward end 148 of the board. Footpad 226 is coupled directly toframe 104, and supported thereon. Power supply 164 is housed underfootpad 226, inside an upper battery cover 228 and a lower batteryhousing 230. An undercarriage is provided by the battery housing and/oran extension of rear bumper 124, or in some examples by a separatehousing or expanse of rigid material.

As depicted in FIG. 10 , each of the concave footpads may include arigid substrate 223 with a compliant or resilient layer 225 disposedthereon. The rigid substrate may include any suitable material andstructure configured to support a rider's weight, such as athermoplastic polymer, e.g., acrylonitrile butadiene styrene (ABS),polyethylene (PE), polyvinyl chloride (PVC), and/or the like. Theresilient layer may comprise an elastomer, e.g., a synthetic and/ornatural rubber, or another suitably resilient material, e.g., ahigh-density foam. In some examples, resilient layer 225 is overmoldedonto rigid substrate 223.

Rigid substrate 223 and resilient layer 225 may be coupled by one ormore mating features configured to provide structural security andadditional mechanical stability. For example, resilient layer 225 mayinclude a plurality of downward-facing protrusions 227 received incorresponding apertures 229 in the rigid substrate. Additionally, oralternatively, resilient layer 225 may have a connecting rail 231 matedwith a corresponding slot structure 233 of rigid substrate 223, suchthat, once formed together (e.g., by injection molding the resilientlayer onto and through the rigid substrate), the resilient layer and therigid substrate comprise a single piece incapable of nondestructivedisassembly.

As shown in FIGS. 11 and 12 , footpad 222 and footpad 226 have a rampedprofile in the direction of travel, such that an end portion of eachfootpad is ramped upward in a direction away from the wheel. In someexamples, one or both footpads may be unramped or differently ramped. Inthe present example, the ramped profile is concave-up in thelongitudinal direction. FIGS. 11 and 12 show the footpad with membraneswitch 220 installed. One or both of footpads 222 and 226 may includethe membrane switch, although examples depicted herein have the membraneswitch on a front footpad. In some examples, the footpad is monolithicand made from a single material, instead of the two-layered, interlockedversion described above.

Whether or not the footpad is ramped in a longitudinal direction,footpad 222 and footpad 226 may be concave, having a concave-up profilein a heel-toe direction (i.e., laterally). The heel-toe concave-upprofile may also be described as being in a direction parallel to theaxis of rotation of the wheel, in a direction parallel to the axle, in adirection orthogonal to the direction of travel, and/or in a directionparallel to the pitch or tilt axis. In some examples, one or bothfootpads are laterally concave and longitudinally ramped. In someexamples, one or both footpads are concave-up in more than one directionor on more than one axis. In some examples, one or both footpads have alongitudinal profile that is ramped and concave-up, and a lateralprofile that is concave-up.

In this context, a concave footpad (i.e., concave-up laterally) may haveany suitable smooth, continuous, and/or faceted concave cross-sectionalprofile. For example, footpad 222 and/or footpad 226 may have a radialconcavity (e.g., having a generally constant radius of curvature), aprogressive concavity (e.g., with a smaller radius of curvature closerto lateral edges than at the center), a W-shaped concavity (e.g., with araised portion in the center), or a tub-shaped or flat-cave concavity(e.g., with a generally flat center and raised lateral edges).

Membrane switch 220 is disposed on the concave front footpad, e.g.,between resilient layer 225 and an upper layer of grip tape, andtherefore has a similarly concave profile to conform to the footpad.Membrane switch 220 comprises a plastic (e.g., waterproof) laminatehousing one or more (e.g., two) force sensitive resistors or otherpressure sensors. Membrane switch 220 is an expanse sized and configuredto enable simultaneous detection of a toe portion and a heel portion ofa rider's foot. Membrane switch 220 comprises a first pressuretransducer 220A configured to detect pressure from a first (e.g., toe)portion of the rider's foot, and a second pressure transducer 220Bconfigured to detect pressure from a second (e.g., heel) portion of therider's foot. In other words, the membrane switch is sized and shapedsuch that one pressure sensor may be disposed under a toe region of thefootpad and the other pressure sensor may be disposed under a heelregion of the footpad, such that the presence and stance of a rider canbe detected based on which sensor or sensors are activated. Althoughtransducer 220A and transducer 220B have been described as the “toe” and“heel” sensors, the roles of these transducers may be reversed dependingon user preference or riding style, e.g., by way of a user-configurablesetting.

Membrane switch 220 may be bendable (or flexible, e.g., slightlyflexible) in one direction (e.g., on one axis), but may not be capableof compound curvature (e.g., simultaneously on two or more axes) withoutsuffering stress and/or possible failure (e.g., sensor damage).Accordingly, as shown in FIG. 13 , membrane switch 220 includes a pairof slots 221 to facilitate conforming to the curvature of footpad 222and relieve stress on the membrane caused by conforming to theunderlying concavity and/or ramped profile of the footpad. Membraneswitch 220 has a pair of angled slots in an outer end, forming an endportion and two side portions, such that the side portions of themembrane switch are configured to bend upward to conform to the concaveprofile of the footpad and the end portion of the membrane switch isconfigured to bend upward to conform to the ramped profile. The angledslots are each oriented from an outer corner of the membrane toward acentral area of the membrane. More or fewer slots may be utilized,depending on the desired concavity and conformity. Corresponding ribs235 (AKA ridges) protrude upward from resilient layer 225 to accommodateslots 221, e.g., to guide placement and minimize unwanted movement ofmembrane switch 220.

The concave surface of the footpads may be formed by multiple slopedportions or facets, wherein each facet is planar or has substantialcurvature only in a single direction. In some examples, sensor traces ofthe membrane switch are aligned with the direction of curvature toprevent buckling. In some examples, computational flattening is utilizedto convert the curved surface into a flat pattern for manufacturing themembrane switch.

An inboard end of deck portion 106 may be open or uncovered. Thisopening is covered or substantially sealed, and interior components areprotected, by a skirt portion or downward flange of the fender. Thefender further includes a peripheral flange configured to seat on frame104 and be coupled thereto, e.g., by fasteners such as screws or bolts.A dome or arch portion of the fender extends from front and rear ends ofthe peripheral flange, and is configured to overarch tire 114 from frontto rear. On one side, corresponding to the side where handle 150 ismounted, a beveled edge is provided in an inboard side of the flange, tofacilitate placement of the handle into the carrying position. A notchis formed in an end of the peripheral flange, such that the notchcorresponds with a notch of footpad 222 to form a slot.

Alternatively, a fender substitute (AKA the “fender delete”) may beinstalled in place of the full fender. The fender substitute includes askirt portion, a peripheral flange, beveled edge, and a notch, allsubstantially as described above with respect to the fender.

The fender and fender delete are configured to cover and protect theframe members, manage the gap around the tire (e.g., for safety andaesthetics), to snap onto the axle mounting blocks for additionalretention, and to provide additional protection from water/mud ingressinto motor controller 166 through the open end of deck portion 106.

A tire pressure sensor 298 may be included in vehicle 100, and coupledelectrically/electronically to a pressure valve 299 of tire 114. Tirepressure sensor 298 may include any suitable pressure sensor coupled toor integrated into tire 114, e.g., at the valve stem, and configured tosense pneumatic pressure in tire 114. Sensed pressure is communicated,e.g., wirelessly, to the controller and/or a networked device such as auser's mobile digital device (e.g., a smart phone).

A tire pressure management system (TPMS) may be employed on-vehicleand/or as part of a software application (app) running on the mobiledevice. The management system may function to log tire pressures,display or otherwise provide high- or low-pressure warnings or alerts,and/or communicate the tire pressure for further analysis and display.For example, the TPMS may provide an analysis of the vehicle's rangeefficiency (e.g., measured in Wh/mi) as a function of the sensed tirepressure. In some examples, tire pressure sensor 298 may communicatetire pressure information to motor controller 166, such that, e.g., inthe case of unsafe tire pressure, the motor controller is configured tobring the vehicle to a safe stop.

B. Illustrative Control System

FIG. 22 is a block diagram of various illustrative electrical componentsof vehicle 100, including onboard controls, some or all of which may beincluded in the vehicle. The electrical components may include a powersupply management system 300 having a battery management system (BMS), adirect current to direct current (DC/DC) converter 302, a brushlessdirect current (BLDC) drive logic 304, a power stage 306, one or more3-axis accelerometers 188, one or more 3-axis gyros 186, one or moreHall sensors 308, and/or a motor temperature sensor 310. DC/DC converter302, BLDC drive logic 304, and power stage 306 may be included in and/orcoupled to motor controller 166. In some examples, motor controller 166may comprise a variable-frequency drive and/or any other suitable drive.Gyro(s) 186 and accelerometer(s) 188 may be included in sensors 176.

Active balancing (or self-stabilization) of the electric vehicle may beachieved through the use of a feedback control loop or mechanism. Thefeedback control mechanism may include sensors 176, which may beelectrically coupled to and/or included in motor controller 166.Preferably, the feedback control mechanism includes aProportional-Integral-Derivative (PID) control scheme using one or moregyros (e.g., gyro(s) 186) and one or more accelerometers (e.g.,accelerometer(s) 188). Gyro 186 may be configured to measure a pivotingof the foot deck about its pitch axis. Gyro 186 and accelerometer 188may be collectively configured to estimate (or measure, or sense) a leanangle of board 102, such as an orientation of the foot deck about thepitch, roll and/or yaw axes. In some embodiments, gyro 186 andaccelerometer 188 may be collectively configured to sense orientationinformation sufficient to estimate the lean angle of frame 104 includingpivotation about the pitch, roll and/or yaw axes.

As mentioned above, orientation information of board 102 may be measured(or sensed) by gyro 186 and accelerometer 188. The respectivemeasurements (or sense signals) from gyro 186 and accelerometer 188 maybe combined using a complementary or Kalman filter to estimate a leanangle of board 102 (e.g., pivoting of board 102 about the pitch, roll,and/or yaw axes, with pivoting about the pitch axis corresponding to apitch angle (about axle 126), pivoting about the roll axis correspondingto a roll or heel-toe angle, and pivoting about the yaw axiscorresponding to a side-to-side yaw angle) while filtering out theimpacts of bumps, road texture and disturbances due to steering inputs.For example, gyro 186 and accelerometer 188 may be connected tomicrocontroller 174, which may be configured to correspondingly measuremovement of board 102 about and/or along the pitch, roll, and/or yawaxes.

Alternatively, the electronic vehicle may include any suitable sensorand feedback control loop configured to self-stabilize a vehicle, suchas a 1-axis gyro configured to measure pivotation of the board about thepitch axis, a 1-axis accelerometer configured to measure a gravityvector, and/or any other suitable feedback control loop, such as aclosed-loop transfer function. Additional accelerometer and gyro axesmay allow improved performance and functionality, such as detecting ifthe board has rolled over on its side or if the rider is making a turn.

The feedback control loop may be configured to drive motor 144 to reducean angle of board 102 with respect to the ground. For example, if arider were to angle board 102 downward, so that first deck portion 106was ‘lower’ than second deck portion 108 (e.g., if the rider pivotedboard 102 counterclockwise (CCW) about axle 126 in FIG. 2 ), then thefeedback loop may drive motor 144 to cause CCW rotation of tire 114about the pitch axis (i.e., axle 126) and a clockwise force on board102.

Thus, motion of the electric vehicle may be achieved by the riderleaning his or her weight toward a selected (e.g., “front”) foot.Similarly, deceleration may be achieved by the rider leaning toward theother (e.g., “back” foot). Regenerative braking can be used to slow thevehicle, as discussed further below. Sustained operation may be achievedin either direction by the rider maintaining their lean toward eitherselected foot.

As indicated in FIG. 22 , microcontroller 174 may be configured to senda signal to brushless DC (BLDC) drive logic 304, which may communicateinformation relating to the orientation and motion of board 102. BLDCdrive logic 304 may then interpret the signal and communicate with powerstage 306 to drive motor 144 accordingly. Hall sensors 308 may send asignal to the BLDC drive logic to provide feedback regarding asubstantially instantaneous rotational rate of the rotor of motor 144.Motor temperature sensor 310 may be configured to measure a temperatureof motor 144 and send this measured temperature to logic 304. Logic 304may limit an amount of power supplied to motor 144 based on the measuredtemperature of motor 144 to prevent the motor from overheating.

In some examples, microcontroller 174 (or another suitable portion ofthe control system) provides feedback to the user when an error isdetected, the vehicle is operating in an unsafe condition, powersupplied to motor 144 is about to be limited, the motor is at risk ofoverheating or overdrawing current, battery charge is low, and/or otherpotentially dangerous situations. For example, microcontroller 174 mayprovide haptic feedback (e.g., via a vibration motor within board 102),audible feedback (e.g., via a speaker within board 102), and/or visualfeedback (e.g., via color changes and/or light patterns usingilluminators 206). In some examples, feedback may be provided to theuser via a mobile digital device such as a smartphone alert.

Certain modifications to the PID loop or other suitable feedback controlloop may be incorporated to improve performance and safety of theelectric vehicle. For example, integral windup may be prevented bylimiting a maximum integrator value, and an exponential function may beapplied to a pitch error angle (e.g., a measured or estimated pitchangle of board 102).

Alternatively or additionally, some embodiments may include neuralnetwork control, fuzzy control, genetic algorithm control,linear-quadratic regulator control, state-dependent Riccati equationcontrol, and/or other control algorithms. In some embodiments, absoluteor relative encoders may be incorporated to provide feedback on motorposition.

In some embodiments, a field-oriented control (FOC) or vector controlsystem may be incorporated into the motor controller (e.g., inmicrocontroller 174, drive logic 304, and/or any other suitableprocessing logic of the motor controller). A suitable FOC system may beconfigured to divert excess regenerative current, thereby acting as aprotective mechanism for the battery.

As mentioned above, during turning, the pitch angle can be modulated bythe heel-toe angle (e.g., pivoting of the board about the roll axis),which may improve performance and prevent a front inside edge of board102 from touching the ground. In some embodiments, the feedback loop maybe configured to increase, decrease, or otherwise modulate therotational rate of the tire if the board is pivoted about the rolland/or yaw axes. This modulation of the rotational rate of the tire mayexert an increased normal force between a portion of the board and therider, and may provide the rider with a sense of “carving” when turning,similar to the feel of carving a snowboard through snow or a surfboardthrough water.

Once the rider has suitably positioned themselves on the board, thecontrol loop may be configured to not activate until the rider moves theboard to a predetermined orientation. For example, an algorithm may beincorporated into the feedback control loop, such that the control loopis not active (e.g., does not drive the motor) until the rider usestheir weight to bring the board up to an approximately level orientation(e.g., zero-degree pitch angle). Once this predetermined orientation isdetected, the feedback control loop may be enabled (or activated) tobalance the electric vehicle and to facilitate a transition of theelectric vehicle from a stationary mode (or configuration, or state, ororientation) to a moving mode (or configuration, or state, ororientation).

With continued reference to FIG. 22 , the various electrical componentsmay be configured to manage power supply 164. For example, the batterymanagement system of power supply management system 300 is configured toprotect batteries of power supply 164 from being overcharged,over-discharged, and/or short-circuited.

For example, a high voltage threshold may be instituted to stop and/orprevent charging at a selected battery charge percentage (e.g., 95%),and a low voltage threshold may be configured to stop discharging at aselected battery charge percentage (e.g., 5%). The high voltagethreshold and low voltage threshold may be configured at the cell level,the battery pack level, or both. In some examples, the high voltagethreshold allows more room for energy absorption via regenerativebraking by limiting possible overcharging, such as when recently removedfrom the charger. By raising the low voltage threshold and reducing thehigh voltage threshold, the cycle life of the battery may be extended.The high voltage threshold and low voltage threshold may be selectivelyenabled and modified by the user, e.g., through a networked device suchas a user's mobile digital device (e.g., smart phone).

System 300 may monitor battery health, may monitor a state of charge inpower supply 164, and/or may increase the safety of the vehicle. Powersupply management system 300 (AKA a battery charging system) may beconnected between a user-accessible charge plug receptacle 172 (AKAcharge port) of vehicle 100 and power supply 164. The rider (or otheruser) may couple a charger to plug receptacle 172 and re-charge powersupply 164 via system 300.

As shown in FIGS. 2, 9, 12 , and elsewhere, charge receptacle 172includes three electrical pins configured to mate with female connectorsin a corresponding charging plug connectable to the charging port. Thethree pins include a ground pin 173, an input pin 175, and a third pin177 (AKA the identification (ID) pin). The charging plug may be acomponent of an external charging circuit 179, e.g., comprising analternating current (AC) to direct current (DC) converter (AKA adapter)that receives AC power from a standard home outlet or the like.

The external charging circuit is configured to communicate anidentification (ID) signal to the ID pin of the charging port.Accordingly, the charging system of the vehicle receives theidentification signal via the third pin, and selectively enablescharging of the battery based on the received identification signal. Inother words, to enable charging of the rechargeable battery, system 300(or the BMS of system 300) checks that the signal applied to the ID pinmatches a known, expected value (or series of values and/or timing ofthe series of values). In some examples, the identification signal is aspecific voltage, current, or both. System 300 therefore confirmslegitimacy of the charger by confirming that the correct identificationsignal has been applied to the ID pin.

In some examples, the correct (i.e., expected) ID signal varies withrespect to time. For example, the correct ID signal may change accordingto a known sequence of values, a known continuous function, or the like.In some examples, the ID signal utilizes a form of pulse widthmodulation, in which a selected value and duty cycle are expected by theBMS. For example, the external charging unit may provide an ID signal inpulses at regular or calculable intervals. The magnitude of the IDsignal may be higher or lower than a background value, or the ID signaland the background may have overlapping values.

In operation, when an input voltage is detected on the input pin, theBMS checks for the identification signal on the third pin. If the IDsignal matches the expected value, then the BMS enables charging of thevehicle. Otherwise, the BMS does not enable charging of the vehicle. Insome examples, the charging circuit of the vehicle is disabled bydefault, with the BMS configured to enable the charging circuit of thevehicle only when a proper ID signal is present from the charger. Insome examples, the BMS is configured to actively or affirmativelydisable the charging circuit of the vehicle when a proper ID signal isabsent.

Accordingly, a device for charging the battery of an electric vehicle(e.g., external charging circuit 179) may include a first plug havingthree conductors, wherein the first plug is configured to mate with athree-conductor charging receptacle of an electric vehicle, and thethree (e.g., female) conductors of the first plug include a directcurrent (DC) output conductor, a ground, and an identification signalconductor. The device may further include a second plug configured tomate with an alternating-current (AC) outlet, and an AC to DC converterconfigured to receive an AC current from the second plug and to providea DC current to the first plug. Furthermore, the device may include asignal generator configured to produce an identification signalcomprising a selected value (e.g., a voltage or electrical currentmagnitude) pulsed periodically in accordance with a selected duty cycle.The signal generator is further configured to provide the identificationsignal to the identification signal conductor of the first plug.

Accordingly, a method for charging the battery of an electric vehicle(e.g., vehicle 100) may include coupling an alternating current (AC) todirect current (DC) adapter (e.g., external charging circuit 179) to acharging port of the vehicle (e.g., charge receptacle 172). The methodincludes applying a charging voltage to a first conductor of thecharging port, using the AC to DC adapter, and communicating anidentification signal to a second conductor of the charging port,wherein the identification signal is configured to match anidentification signal expected by the battery management system (BMS) ofthe vehicle. The method may include generating the identification signalin response to sensing that the adapter has been coupled to the chargingport. In some examples, the first and second conductors of the chargingport are male connectors (e.g., pins). In some examples, the chargingport has a third male connector in the form of a ground pin.

The identification signal comprises a selected value (e.g., a voltageand/or current magnitude) pulsed periodically in accordance with aselected duty cycle. Finally, in response to the BMS enabling thecharging system of the vehicle, the method includes charging thesecondary battery of the vehicle using the AC to DC adapter. The methodmay further include coupling the AC to DC adapter to a source of ACelectricity (e.g., a household electrical outlet). In some examples, theAC to DC adapter has a first plug configured to mate with the chargingport of the electric vehicle and a second plug configured to mate withan AC electrical outlet.

To begin operating the vehicle, power switch 170 may be activated (e.g.,by the rider). Activation of switch 170 may send a power-on signal toconverter 302. In response to the power-on signal, converter 302 mayconvert direct current from a first voltage level provided by powersupply 164 to one or more other voltage levels. The other voltage levelsmay be different than the first voltage level. Converter 302 may beconnected to the other electrical components via one or more electricalconnections to provide these electrical components with suitablevoltages.

Converter 302 (or other suitable circuitry) may transmit the power-onsignal to microcontroller 174. In response to the power-on signal,microcontroller may initialize sensors 176, and rider detection device168.

The electric vehicle may include one or more safety mechanisms, such aspower switch 170 and/or rider detection device 168 to ensure that therider is on the board before engaging the feedback control loop. In someembodiments, rider detection device 168 may be configured to determineif the rider's foot or feet are disposed on the foot deck, and to send asignal causing motor 144 to enter an active state when the rider's footor feet are determined to be disposed on the foot deck.

Rider detection device 168 may include any suitable mechanism,structure, or apparatus for determining whether the rider is on theelectric vehicle. For example, device 168 may include one or moremechanical buttons, one or more capacitive sensors, one or moreinductive sensors, one or more optical switches, one or moreforce-resistive sensors, and/or one or more strain gauges. Riderdetection device 168 may be located on or under either or both of firstand second deck portions 106, 108. In some examples, the one or moremechanical buttons or other devices may be pressed directly (e.g., if onthe deck portions), or indirectly (e.g., if under the deck portions), tosense whether the rider is on board 102. In some examples, the one ormore capacitive sensors and/or the one or more inductive sensors may belocated on or near a surface of either or both of the deck portions, andmay correspondingly detect whether the rider is on the board via achange in capacitance or a change in inductance. In some examples, theone or more optical switches may be located on or near the surface ofeither or both of the deck portions. The one or more optical switchesmay detect whether the rider is on the board based on an optical signal.In some examples, the one or more strain gauges may be configured tomeasure board or axle flex imparted by the rider's feet to detectwhether the rider is on the board. In some embodiments, device 168 mayinclude a hand-held “dead-man” switch.

If device 168 detects that the rider is suitably positioned on theelectric vehicle, then device 168 may send a rider-present signal tomicrocontroller 174. The rider-present signal may be the signal causingmotor 144 to enter the active state. In response to the rider-presentsignal (and/or the board being moved to the level orientation),microcontroller 174 may activate the feedback control loop for drivingmotor 144. For example, in response to the rider-present signal,microcontroller 174 may send board orientation information (ormeasurement data) from sensors 176 to logic 304 for powering motor 144via power stage 306.

In some embodiments, if device 168 detects that the rider is no longersuitably positioned or present on the electric vehicle, device 168 maysend a rider-not-present signal to microcontroller 174. In response tothe rider-not-present signal, circuitry of vehicle 100 (e.g.,microcontroller 174, logic 304, and/or power stage 306) may beconfigured to reduce a rotational rate of the rotor relative to thestator to bring vehicle 100 to a stop. For example, the electric coilsof the rotor may be selectively powered to reduce the rotational rate ofthe rotor. In some embodiments, in response to the rider-not-presentsignal, the circuitry may be configured to energize the electric coilswith a relatively strong and/or substantially continuously constantvoltage, to lock the rotor relative to the stator, to prevent the rotorfrom rotating relative to the stator, and/or to bring the rotor to asudden stop.

In some embodiments, the vehicle may be configured to actively drivemotor 144 even though the rider may not be present on the vehicle (e.g.,temporarily), which may allow the rider to perform various tricks. Forexample, device 168 may be configured to delay sending therider-not-present signal to the microcontroller for a predeterminedduration of time, and/or the microcontroller may be configured to delaysending the signal to logic 304 to cut power to the motor for apredetermined duration of time.

C. Illustrative Combinations and Additional Examples

This section describes additional aspects and features of the vehicleand control system described herein, presented without limitation as aseries of paragraphs, some or all of which may be alphanumericallydesignated for clarity and efficiency. Each of these paragraphs can becombined with one or more other paragraphs, and/or with disclosure fromelsewhere in this application, including the materials incorporated byreference in the Cross-References, in any suitable manner. Some of theparagraphs below expressly refer to and further limit other paragraphs,providing without limitation examples of some of the suitablecombinations.

A0. A self-balancing electric vehicle, comprising:

-   -   a board including a frame, a first deck portion disposed at a        first end portion of the frame, and a second deck portion        disposed at a second end portion of the frame, the first and        second deck portions each configured to receive a left or right        foot of a rider oriented generally perpendicular to a direction        of travel of the board;    -   a wheel assembly including a wheel rotatable about an axle,        wherein the wheel is disposed between and extends above and        below the first and second deck portions;    -   a motor assembly configured to rotate the wheel about the axle        to propel the vehicle; and    -   an electronic controller configured to receive orientation        information of the board measured by at least one sensor and to        cause the motor assembly to propel the vehicle based on the        orientation information;    -   wherein the first deck portion includes a concave first footpad        having a concave-up profile in a heel-toe direction.

A1. The vehicle of A0, wherein the first footpad has a ramped profile inthe direction of travel, such that an end portion of the first footpadis ramped upward in a direction away from the wheel.

A2. The vehicle of A1, wherein the ramped profile is concave-up.

A3. The vehicle of any one of AC through A2, further including a riderdetection system comprising a membrane switch having one or morepressure transducers; wherein the membrane switch is layered onto theconcave first footpad.

A4. The vehicle of A3 wherein the membrane switch has a pair of angledslots in an outer end, forming an end portion and two side portions,such that the side portions of the membrane switch are configured tobend upward to conform to the concave profile of the first footpad andthe end portion of the membrane switch is configured to bend upward toconform to the ramped profile of the first footpad.

A5. The vehicle of A4, wherein the angled slots are each oriented froman outer corner of the membrane toward a central area of the membrane.

A6. The vehicle of A4 or A5, wherein the footpad includes a pair ofridges configured to fit into the slots of the membrane switch.

A7. The vehicle of any one of A3 through A6, wherein the membrane switchhas a waterproof outer housing.

A8. The vehicle of any one of A3 through A7, wherein the membrane switchcomprises a first pressure transducer configured to detect pressure froma toe portion of a rider's foot, and a second pressure transducerconfigured to detect pressure from a heel portion of the rider's foot.

A9. The vehicle of A8, wherein at least one of the pressure transducerscomprises a force sensitive resistor.

A10. The vehicle of any one of AC through A9, wherein the first footpadcomprises a resilient layer covering a rigid base.

A11. The vehicle of A10, wherein the rigid base comprises a plastic.

A12. The vehicle of A10 or A11, wherein the resilient layer comprises arubber material.

A13. The vehicle of A10 or A11, wherein the resilient layer comprises afoam.

A14. The vehicle of any one of A10 through A13, wherein the resilientlayer is overmolded onto the rigid base.

A15. The vehicle of any one of A10 through A14, wherein the rigid baseincludes one or more apertures.

A16. The vehicle of A15, wherein the resilient layer includes one ormore protrusions received by the one or more underlying apertures of therigid base.

A17. The vehicle of any one of AC through A16, wherein a concave riderdetection switch is disposed between the first concave footpad and anupper layer of grip tape.

A18. The vehicle of any one of AC through A17, wherein the second deckportion comprises a second concave footpad.

B0. A self-balancing electric vehicle, comprising:

-   -   a wheel assembly including a wheel having an axis of rotation;    -   a board including an aperture to accommodate the wheel, such        that the board is tiltable about the wheel, first and second        deck portions of the board each configured to receive a left or        right foot of a rider oriented generally parallel to the axis of        rotation of the wheel;    -   an electric hub motor configured to drive the wheel; and    -   a controller configured to receive orientation information        indicating an orientation of the board and to cause the hub        motor to propel the board based on the orientation information;    -   wherein the first deck portion includes a concave first footpad        having a concave-up profile in a direction parallel to the axis        of rotation of the wheel.

B1. The vehicle of B0, wherein the first footpad has a ramped profile,such that an end portion of the first footpad is ramped upward in adirection away from the wheel.

B2. The vehicle of B1, wherein the ramped profile is concave-up.

B3. The vehicle of any one of BC through B2, further including a riderdetection system comprising a membrane switch having one or morepressure transducers; wherein the membrane switch is disposed on theconcave first footpad.

B4. The vehicle of B3, wherein the membrane switch has a pair of angledslots in an outer end, forming an end portion and two side portions,such that the side portions of the membrane switch are configured tobend upward to conform to the concave profile of the first footpad andthe end portion of the membrane switch is configured to bend upward toconform to the ramped profile of the first footpad.

B5. The vehicle of B4, wherein the angled slots are each oriented froman outer corner of the membrane toward a central area of the membrane.

B6. The vehicle of any one of B3 to B5, wherein the membrane switch hasa waterproof outer housing.

B7. The vehicle of any one of B3 through B6, wherein the membrane switchcomprises a first pressure transducer configured to detect pressure froma toe portion of the rider's foot, and a second pressure transducerconfigured to detect pressure from a heel portion of the rider's foot.

B8. The vehicle of B7, wherein at least one of the pressure transducerscomprises a force sensitive resistor.

B9. The vehicle of B4 or B5, wherein the footpad includes a pair ofdiagonal ridges configured to fit into the slots of the membrane switch.

B10. The vehicle of any one of BC through B9, wherein the first footpadcomprises a resilient layer covering a rigid base.

B11. The vehicle of B10, wherein the rigid base comprises a plastic.

B12. The vehicle of B10 or B11, wherein the resilient layer comprises arubber material.

B13. The vehicle of B10 or B11, wherein the resilient layer comprises afoam.

B14. The vehicle of any one of B10 through B13, wherein the resilientlayer is overmolded onto the rigid base.

B15. The vehicle of any one of B10 through B14, wherein the rigid baseincludes one or more apertures.

B16. The vehicle of B15, wherein the resilient layer includes one ormore protrusions received by the one or more underlying apertures of therigid base.

B17. The vehicle of any one of BC through B16, wherein a concave riderdetection switch is disposed between the first concave footpad and anupper layer of grip tape.

B18. The vehicle of any one of BC through B17, wherein the second deckportion comprises a second concave footpad.

C0. A self-balancing electric vehicle comprising:

-   -   a wheel assembly including a wheel driven by a hub motor about        an axle;    -   a board including an aperture to accommodate the wheel, such        that the board is tiltable about the wheel, first and second        deck portions of the board each configured to receive a left or        right foot of a rider oriented generally parallel to the axle;        and    -   a controller configured to cause the hub motor to propel the        board based on board orientation information;    -   wherein the first deck portion includes a concave first footpad        having a concave-up profile in a direction parallel to the axle.

C1. The vehicle of C0, wherein the first footpad has a ramped profile,such that an end portion of the first footpad is ramped upward in adirection away from the wheel.

C2. The vehicle of C1, wherein the ramped profile is concave-up.

C3. The vehicle of any one of C0 through C2, further including a riderdetection system comprising a membrane switch having one or morepressure transducers; wherein the membrane switch is disposed on theconcave first footpad.

C4. The vehicle of C3, wherein the membrane switch has a pair of angledslots in an outer end, forming an end portion and two side portions,such that the side portions of the membrane switch are configured tobend upward to conform to the concave profile of the first footpad andthe end portion of the membrane switch is configured to bend upward toconform to the ramped profile of the first footpad.

C5. The vehicle of C4, wherein the angled slots are each oriented froman outer corner of the membrane toward a central area of the membrane.

C6. The vehicle of any one of C3 to C5, wherein the membrane switch hasa waterproof outer housing.

C7. The vehicle of any one of C3 through C6, wherein the membrane switchcomprises a first pressure transducer configured to detect pressure froma toe portion of the rider's foot, and a second pressure transducerconfigured to detect pressure from a heel portion of the rider's foot.

C8. The vehicle of C7, wherein at least one of the pressure transducerscomprises a force sensitive resistor.

C9. The vehicle of C4 or C5, wherein the footpad includes a pair ofdiagonal ridges configured to fit into the slots of the membrane switch.

C10. The vehicle of any one of C0 through C9, wherein the first footpadcomprises a resilient layer covering a rigid base.

C11. The vehicle of C10, wherein the rigid base comprises a plastic.

C12. The vehicle of C10 or C11, wherein the resilient layer comprises arubber material.

C13. The vehicle of C10 or C11, wherein the resilient layer comprises afoam.

C14. The vehicle of any one of C10 through C13, wherein the resilientlayer is overmolded onto the rigid base.

C15. The vehicle of any one of C10 through C14, wherein the rigid baseincludes one or more apertures.

C16. The vehicle of C15, wherein the resilient layer includes one ormore protrusions received by the one or more underlying apertures of therigid base.

C17. The vehicle of any one of C0 through C16, wherein a concave riderdetection switch is disposed between the first concave footpad and anupper layer of grip tape.

C18. The vehicle of any one of C0 through C17, wherein the second deckportion comprises a second concave footpad.

D0. A self-balancing electric vehicle, comprising:

-   -   a board including a frame, a first deck portion disposed at a        first end portion of the frame, and a second deck portion        disposed at a second end portion of the frame, the first and        second deck portions each configured to receive a left or right        foot of a rider oriented generally perpendicular to a direction        of travel of the board;    -   a wheel assembly including a wheel rotatable about an axle,        wherein the wheel is disposed between and extends above and        below the first and second deck portions;    -   a motor assembly configured to rotate the wheel about the axle        to propel the vehicle;    -   an electronic controller configured to receive orientation        information of the board measured by at least one sensor and to        cause the motor assembly to propel the vehicle based on the        orientation information; and    -   a bumper coupled to the first end portion of the frame, wherein        the bumper comprises a body configured to form a distal external        end of the board, and an expanse extending from the body to form        a lower external surface of the board;    -   wherein each lateral edge of the expanse of the bumper includes        a lengthwise channel configured to slidingly mate with a        corresponding inward protrusion of a respective side rail of the        frame.

D1. The vehicle of D0, wherein the body of the bumper is held to theframe by one or more removable fasteners, and an opposite end of thebumper is supported entirely by the side rails and channels.

D2. The vehicle of D0 or D1, wherein the bumper comprises ABS plastic.

D3. The vehicle of any one of D0 through D2, wherein the expanse of thebumper includes an aperture forming a carrying handle.

D4. The vehicle of D3, wherein an electronics enclosure disposed abovethe expanse of the bumper includes a recess in registration with theaperture of the bumper.

D5. The vehicle of D4, wherein the recess in the electronics enclosureis a blind hole having dimensions corresponding to the aperture in thebumper.

D6. The vehicle of any one of D0 through D5, wherein the inwardprotrusion runs along a discrete length of each of the side rails.

E0. A self-balancing electric vehicle, comprising:

-   -   a wheel assembly including a wheel having an axis of rotation;    -   a board including an opening to accommodate the wheel, such that        the board is tiltable about the wheel, first and second deck        portions of the board each configured to receive a left or right        foot of a rider oriented generally parallel to the axis of        rotation of the wheel;    -   an electric hub motor configured to drive the wheel;    -   a controller configured to receive orientation information        indicating an orientation of the board and to cause the hub        motor to propel the board based on the orientation information;        and    -   a bumper coupled to the first deck portion, wherein the bumper        comprises a body configured to form a distal external end of the        board, and an expanse extending from the body to form a lower        external surface of the board;    -   wherein each lateral edge of the expanse of the bumper includes        a lengthwise channel configured to slidingly mate with a        corresponding inward protrusion of a respective side rail of the        board.

E1. The vehicle of E0, wherein the body of the bumper is held to theboard by one or more removable fasteners, and an opposite end of thebumper is supported entirely by the side rails and channels.

E2. The vehicle of E0 or E1, wherein the bumper comprises ABS plastic.

E3. The vehicle of any one of E0 through E2, wherein the expanse of thebumper includes an aperture forming a carrying handle.

E4. The vehicle of E3, wherein an electronics enclosure disposed abovethe expanse of the bumper includes a recess in registration with theaperture of the bumper.

E5. The vehicle of E4, wherein the recess in the electronics enclosureis a blind hole having dimensions corresponding to the aperture in thebumper.

E6. The vehicle of any one of E0 through E5, wherein the inwardprotrusion runs along a discrete length of each of the side rails.

F0. A self-balancing electric vehicle comprising:

-   -   a wheel assembly including a wheel driven by a hub motor about        an axle;    -   a board including a central opening to accommodate the wheel,        such that the board is tiltable about the wheel, first and        second deck portions of the board each configured to receive a        left or right foot of a rider oriented generally parallel to the        axle; and    -   a controller configured to cause the hub motor to propel the        board based on board orientation information;    -   a bumper coupled to the first deck portion, wherein the bumper        comprises a body configured to form a distal external end of the        board, and an expanse extending from the body to form a lower        external surface of the board;    -   wherein each lateral edge of the expanse of the bumper includes        a lengthwise channel configured to slidingly mate with a        corresponding inward protrusion of a respective side rail of the        board.

F1. The vehicle of F0, wherein the body of the bumper is held to theboard by one or more removable fasteners, and an opposite end of thebumper is supported entirely by the side rails and channels.

F2. The vehicle of F0 or F1, wherein the bumper comprises ABS plastic.

F3. The vehicle of any one of F0 through F2, wherein the expanse of thebumper includes an aperture forming a carrying handle.

F4. The vehicle of F3, wherein an electronics enclosure disposed abovethe expanse of the bumper includes a recess in registration with theaperture of the bumper.

F5. The vehicle of F4, wherein the recess in the electronics enclosureis a blind hole having dimensions corresponding to the aperture in thebumper.

F6. The vehicle of any one of F0 through F5, wherein the inwardprotrusion runs along a discrete length of each of the side rails.

G0. A self-balancing electric vehicle, comprising:

-   -   a board including a frame, a first deck portion disposed at a        first end portion of the frame, and a second deck portion        disposed at a second end portion of the frame, the first and        second deck portions each configured to receive a left or right        foot of a rider oriented generally perpendicular to a direction        of travel of the board;    -   a wheel assembly including a wheel rotatable about an axle,        wherein the wheel is disposed between and extends above and        below the first and second deck portions;    -   a motor assembly configured to rotate the wheel about the axle        to propel the vehicle;    -   an electronic controller configured to receive orientation        information of the board measured by at least one sensor and to        cause the motor assembly to propel the vehicle based on the        orientation information; and    -   a U-shaped bumper coupled to the second deck portion, wherein        the bumper comprises a body configured to form an external end        of the board, and a pair of legs extending from the body to form        lower longitudinal corners of the board;    -   wherein each leg of the bumper includes an inward protrusion        configured to slidingly mate with a corresponding lengthwise        channel of a battery enclosure of the board.

G1. The vehicle of G0, wherein the body of the bumper is held to theboard by one or more removable fasteners, and distal ends of the legs ofthe bumper are supported entirely by the protrusions and channels.

G2. The vehicle of G0 or G1, wherein the battery enclosure extendsdownward farther than adjacent side rails of the board, and the channelsof the battery enclosure are disposed lower than bottom edges of theside rails.

G3. The vehicle of G2, wherein upper surfaces of the legs of the bumperare in contact with the bottom edges of the side rails.

G4. The vehicle of any one of G0 through G3, wherein a lower surface ofthe battery enclosure extends between the two legs of the bumper to forman external surface of the board.

G5. The vehicle of G4, wherein the inward protrusion runs along adiscrete length of each of the legs.

H0. A self-balancing electric vehicle, comprising:

-   -   a wheel assembly including a wheel having an axis of rotation;    -   a board including a central opening to accommodate the wheel,        such that the board is tiltable about the wheel, first and        second deck portions of the board each configured to receive a        left or right foot of a rider oriented generally parallel to the        axis of rotation of the wheel;    -   an electric hub motor coupled to a battery and configured to        drive the wheel; and    -   a controller configured to receive orientation information        indicating an orientation of the board and to cause the hub        motor to propel the board based on the orientation information;    -   a U-shaped bumper coupled to the second deck portion, wherein        the bumper comprises a body configured to form a distal end of        the board, and a pair of legs extending from the body to form        lower longitudinal corners of the board;    -   wherein each leg of the bumper includes an inward protrusion        configured to slidingly mate with a corresponding lengthwise        channel of a battery enclosure of the board.

H1. The vehicle of H0, wherein the body of the bumper is held to theboard by one or more removable fasteners, and distal ends of the legs ofthe bumper are supported entirely by the protrusions and channels.

H2. The vehicle of H0 or H1, wherein the battery enclosure extendsdownward farther than adjacent side rails of the board, and the channelsof the battery enclosure are disposed lower than bottom edges of theside rails.

H3. The vehicle of H2, wherein upper surfaces of the legs of the bumperare in contact with the bottom edges of the side rails.

H4. The vehicle of any one of H0 through H3, wherein a lower surface ofthe battery enclosure extends between the two legs of the bumper to forman external surface of the board.

H5. The vehicle of H4, wherein the inward protrusion runs along adiscrete length of each of the legs.

J0. A self-balancing electric vehicle comprising:

-   -   a wheel assembly including a wheel driven by a hub motor about        an axle;    -   a board including an aperture to accommodate the wheel, such        that the board is tiltable about the wheel, first and second        deck portions of the board each configured to receive a left or        right foot of a rider oriented generally parallel to the axle;        and    -   a controller configured to cause the hub motor to propel the        board based on board orientation information;    -   a U-shaped bumper coupled to the second deck portion, wherein        the bumper comprises a body configured to form a distal external        end of the board, and a pair of legs extending from the body to        form lower longitudinal corners of the board;    -   wherein each leg of the bumper includes an inward protrusion        configured to slidingly mate with a corresponding lengthwise        channel of a battery enclosure of the board.

J1. The vehicle of J0, wherein the body of the bumper is held to theboard by one or more removable fasteners, and distal ends of the legs ofthe bumper are supported entirely by the protrusions and channels.

J2. The vehicle of J0 or J1, wherein the battery enclosure extendsdownward farther than adjacent side rails of the board, and the channelsof the battery enclosure are disposed lower than bottom edges of theside rails.

J3. The vehicle of J2, wherein upper surfaces of the legs of the bumperare in contact with the bottom edges of the side rails.

J4. The vehicle of any one of J0 through J3, wherein a lower surface ofthe battery enclosure extends between the two legs of the bumper to forman external surface of the board.

J5. The vehicle of J4, wherein the inward protrusion runs along adiscrete length of each of the legs.

K0. A self-balancing electric vehicle, comprising:

-   -   a board including a frame, a first deck portion disposed at a        first end portion of the frame, and a second deck portion        disposed at a second end portion of the frame, the first and        second deck portions each configured to receive a left or right        foot of a rider oriented generally perpendicular to a direction        of travel of the board;    -   a wheel assembly including a wheel rotatable about an axle,        wherein the wheel is disposed between and extends above and        below the first and second deck portions;    -   a motor assembly powered by a rechargeable battery and        configured to rotate the wheel about the axle to propel the        vehicle;    -   an electronic controller configured to receive orientation        information of the board measured by at least one sensor and to        cause the motor assembly to propel the vehicle based on the        orientation information; and    -   a battery charging system incorporated into the vehicle and        electrically coupled to the battery, the charging system        comprising a user-accessible charging port having a ground pin,        an input pin, and an identification (ID) pin;    -   wherein the charging system of the vehicle is configured to        receive an identification signal via the ID pin, and to        selectively enable charging of the battery based on the received        identification signal.

K1. The vehicle of K0, wherein a battery management system (BMS) of thecharging system is configured to check for the identification signal onthe ID pin, in response to an input voltage on the input pin.

K2. The vehicle of K1, wherein the BMS is configured to enable thecharging system of the vehicle based on a comparison between theidentification signal and an expected value.

K3. The vehicle of K2, wherein the identification signal changes overtime.

K4. The vehicle of K3, wherein the identification signal comprises theexpected value pulsed in accordance with an expected duty cycle.

K5. The vehicle of K2 or K3, wherein the expected value is an expectedvoltage.

K6. The vehicle of K5, wherein the expected voltage has a magnitudelower than a background voltage.

K7. The vehicle of K2 or K3, wherein the expected value is an expectedcurrent.

K8. The vehicle of K0, wherein a battery management system (BMS) of thecharging system is configured to check for the identification signal onthe ID pin.

K9. The vehicle of K8, wherein the BMS is configured to check for theidentification signal in response to an input voltage on the input pin.

K10. The vehicle of K8, wherein the BMS is configured to enable thecharging system of the vehicle based on a comparison between theidentification signal and an expected value.

K11. The vehicle of K8, wherein the BMS is configured to disable thecharging system of the vehicle based on a comparison between theidentification signal and an expected value.

K12. The vehicle of K11, wherein the identification signal changes overtime.

K13. The vehicle of K12, wherein the identification signal comprises theexpected value pulsed in accordance with an expected duty cycle.

K14. The vehicle of K12 or K13, wherein the expected value is anexpected voltage.

K15. The vehicle of K14, wherein the expected voltage has a magnitudelower than a background voltage.

K16. The vehicle of K12 or K13, wherein the expected value is anexpected current.

K17. The vehicle of any one of K0 through K16, further comprising anexternal charging circuit connectable to the charging port, wherein theexternal charging circuit is configured to communicate theidentification signal to the ID pin of the charging port.

K18. The vehicle of K17, wherein the external charging circuit comprisesan alternating current (AC) to direct current (DC) converter.

L0. A method for charging the battery of an electric vehicle, the methodcomprising:

-   -   coupling an alternating current (AC) to direct current (DC)        adapter to a charging port of an electric vehicle;    -   applying a charging voltage to a first conductor of the charging        port, using the AC to DC adapter;    -   communicating an identification signal to a second conductor of        the charging port, wherein the identification signal is        configured to match an identification signal expected by a        battery management system (BMS) of the vehicle, and wherein the        identification signal comprises a selected value pulsed        periodically in accordance with a selected duty cycle;    -   in response to the BMS enabling the charging system of the        vehicle, charging a secondary battery of the vehicle using the        AC to DC adapter.

L1. The method of L0, further comprising coupling the AC to DC adapterto a source of AC electricity.

L2. The method of L0 or L1, wherein the selected value of theidentification signal comprises a voltage magnitude.

L3. The method of any one of L0 through L2, wherein the selected valueof the identification signal comprises an electrical current magnitude.

L4. The method of any one of L0 through L3, wherein the first and secondconductors of the charging port are male connectors.

L5. The method of L4, wherein the charging port comprises a third maleconnector comprising a ground pin.

L6. The method of any one of L0 through L5, wherein the AC to DC adaptercomprises a first plug configured to mate with the charging port of theelectric vehicle and a second plug configured to mate with an ACelectrical outlet.

L7. The method of any one of L0 through L6, further comprisinggenerating the identification signal in response to sensing that the ACto DC adapter has been coupled to the charging port.

L8. The method of any one of L0 through L7, wherein the electric vehicleis a self-balancing electric vehicle, comprising: a wheel assemblyincluding a wheel having an axis of rotation, a board including acentral opening to accommodate the wheel, such that the board istiltable about the wheel, first and second deck portions of the boardeach configured to receive a left or right foot of a rider orientedgenerally parallel to the axis of rotation of the wheel, an electric hubmotor powered by the secondary battery and configured to drive thewheel, and a controller configured to receive orientation informationindicating an orientation of the board and to cause the hub motor topropel the board based on the orientation information.

M0. A device for charging the battery of an electric vehicle, the devicecomprising:

-   -   a first plug having three conductors, wherein the first plug is        configured to mate with a three-conductor charging receptacle of        an electric vehicle, and the three conductors of the first plug        include a direct current (DC) output conductor, a ground, and an        identification signal conductor;    -   a second plug configured to mate with an alternating-current        (AC) outlet;    -   an AC to DC converter configured to receive an AC current from        the second plug and to provide a DC current to the first plug;        and    -   a signal generator configured to produce an identification        signal comprising a selected value pulsed periodically in        accordance with a selected duty cycle, wherein the signal        generator is further configured to provide the identification        signal to the identification signal conductor of the first plug.

M1. The device of M0, wherein the selected value of the identificationsignal comprises a voltage magnitude.

M2. The device of M0 or M1, wherein the selected value of theidentification signal comprises an electrical current magnitude.

M3. The device of any one of M0 through M2, wherein the three conductorsof the charging port are female connectors.

Advantages, Features, and Benefits

The different embodiments and examples of the electric skateboarddescribed herein provide several advantages over known solutions forproviding comfort, control, and other operating characteristics. Forexample, illustrative embodiments and examples described herein allowfor a membrane switch to be placed on a multi-dimensionally curvedfootpad, enabling both the front and the rear footpads to have a concaveprofile.

Additionally, and among other benefits, illustrative embodiments andexamples described herein allow an increase of user comfort bydecreasing foot fatigue.

Additionally, and among other benefits, illustrative embodiments andexamples described herein allow the user to be better alerted in thecase that an error or an unsafe condition has occurred.

Additionally, and among other benefits, illustrative embodiments andexamples described herein have more than one handle, and therefore allowmultiple options for carrying the vehicle by hand.

Additionally, and among other benefits, illustrative embodiments andexamples described herein allow fewer fasteners to be used in mountingbumpers to the vehicle, thereby decreasing part count and manufacturingcosts while increasing user convenience and simplicity of bumperreplacement.

No known system or device can perform these functions. However, not allembodiments and examples described herein provide the same advantages orthe same degree of advantage.

CONCLUSION

The disclosure set forth above may encompass multiple distinct exampleswith independent utility. Although each of these has been disclosed inits preferred form(s), the specific embodiments thereof as disclosed andillustrated herein are not to be considered in a limiting sense, becausenumerous variations are possible. To the extent that section headingsare used within this disclosure, such headings are for organizationalpurposes only. The subject matter of the disclosure includes all noveland nonobvious combinations and subcombinations of the various elements,features, functions, and/or properties disclosed herein. The followingclaims particularly point out certain combinations and subcombinationsregarded as novel and nonobvious. Other combinations and subcombinationsof features, functions, elements, and/or properties may be claimed inapplications claiming priority from this or a related application. Suchclaims, whether broader, narrower, equal, or different in scope to theoriginal claims, also are regarded as included within the subject matterof the present disclosure.

The invention claimed is:
 1. A footpad set for an electric vehicle,comprising: a first footpad; and a second footpad comprising a membraneswitch having one or more pressure transducers; wherein the first andsecond footpads are each configured to receive a left or right foot of arider oriented generally perpendicular to a direction of travel of avehicle when the footpads are installed in the vehicle; wherein thesecond footpad has a concave-up profile in a heel-toe direction of therider's foot; and wherein the membrane switch has a pair of open-endedslots in an outer end, forming an end portion and two side portions,such that the side portions of the membrane switch are configured tobend upward to conform to the concave-up profile of the footpad.
 2. Thefootpad set of claim 1, wherein the second footpad has a ramped profilein a longitudinal direction, and the end portion of the membrane switchis configured to bend upward to conform to the ramped profile of thesecond footpad.
 3. The footpad set of claim 1, wherein the slots areeach oriented from an outer corner of the membrane toward a central areaof the membrane.
 4. The footpad set of claim 1, wherein the membraneswitch comprises a first pressure transducer configured to detectpressure from a toe portion of a foot of the rider, and a secondpressure transducer configured to detect pressure from a heel portion ofthe same foot of the rider.
 5. The footpad set of claim 1, wherein thesecond footpad comprises a resilient layer overmolded onto a rigid base.6. The footpad set of claim 5, wherein the resilient layer includes oneor more protrusions received by one or more underlying apertures of therigid base.
 7. The footpad set of claim 1, wherein the first footpad hasa concave-up profile in a heel-toe direction of the rider's foot.
 8. Arider detection system for a self-balancing electric vehicle,comprising: a rider detection sensor comprising a membrane switchdisposed on a first footpad configured to receive a left or right footof a rider oriented generally perpendicular to an intended direction oftravel of a vehicle using the rider detection system; a second footpadconfigured to receive a left or right foot of a rider oriented generallyperpendicular to an intended direction of travel of the vehicle; whereinthe first and second footpads each have a concave-up profile in aheel-toe direction, and the membrane switch conforms to the concave-upprofile of the first footpad; and wherein the membrane switch has a pairof open-ended, angled slots in an outer end, such that the membrane hasan end portion and two side portions, and the side portions of themembrane switch are configured to bend upward to conform to the concaveprofile of the first footpad.
 9. The rider detection system of claim 8,wherein the angled slots are each oriented from an outer corner of themembrane toward a central area of the membrane.
 10. The rider detectionsystem of claim 8, wherein the first footpad includes a pair of ridgesconfigured to fit into the slots of the membrane switch.
 11. The riderdetection system of claim 8, wherein the first footpad comprises aresilient layer overmolded onto a rigid base.
 12. The rider detectionsystem of claim 11, wherein the second footpad comprises a resilientlayer overmolded onto a rigid base.
 13. The rider detection system ofclaim 8, wherein the first and second footpads each have an end portionramped upward in a longitudinal direction, and the end portion of themembrane switch is configured to bend upward to conform to the rampedprofile of the first footpad.
 14. A set of footpads for an electricskateboard, comprising: a front footpad comprising a first membraneswitch having one or more pressure transducers; and a rear footpadcomprising a second membrane switch having one or more pressuretransducers; wherein the front and rear footpads are each configured toreceive a left or right foot of a rider oriented generally perpendicularto a direction of travel of a vehicle when the footpads are installed inthe vehicle; wherein the front and rear footpads each have a concave-upprofile in a heel-toe direction of the rider's foot; and wherein firstand second membrane switches each have a pair of open-ended slots in anouter end, forming an end portion and two side portions, such that theside portions of each membrane switch are configured to bend upward toconform to the concave-up profile of the footpad.
 15. The set offootpads of claim 14, wherein the front and rear footpads each have aramped profile in a longitudinal direction, and the end portion of eachmembrane switch is configured to bend upward to conform to the rampedprofile.
 16. The set of footpads of claim 14, wherein the slots in eachof the first and second membrane switches are each oriented from anouter corner of the membrane switch toward a central area of themembrane switch.
 17. The set of footpads of claim 14, wherein each ofthe first and second membrane switches comprises a first pressuretransducer configured to detect pressure from a toe portion of a foot ofthe rider, and a second pressure transducer configured to detectpressure from a heel portion of the same foot of the rider.
 18. The setof footpads of claim 14, wherein the front footpad and the rear footpadeach comprises a resilient layer overmolded onto a rigid base.
 19. Theset of footpads of claim 18, wherein the resilient layer of each footpadincludes one or more protrusions received by one or more underlyingapertures of the rigid base.
 20. The set of footpads of claim 14,wherein the pressure transducers are force sensitive resistors.